Refrigerator Unit and/or a Freezer Unit

ABSTRACT

The present invention relates to a refrigerator unit and/or a freezer unit comprising a cooling tank as well as an evaporator which is accommodated in an evaporator accommodation space in the cooling tank. In accordance with the invention, the refrigerator unit and/or freezer unit is characterized in that the evaporator has a multi-sided jacket of a soft, resilient and/or yielding padding material.

The present invention relates to a refrigerator unit and/or a freezerunit comprising a cooling tank as well as an evaporator, preferably alamellar evaporator, which is accommodated in an evaporatoraccommodation space in the cooling tank.

In such refrigerator units and/or freezer units comprising an evaporatorembedded into the inner tank, said evaporator is seated with arelatively precise fit in the evaporator accommodation space providedtherefor. The clicking noises during operation of the unit represent aproblem which arises in this context. It can be assumed that theseclicking noises are caused by a cyclic freezing of the evaporator to thewalls of the evaporator accommodation space and a release of it againdue to the regular defrosting process. Since a lot of moisture ispresent after a defrosting process, residual drops freeze on between theevaporator surface and the inner tank if a cooling takes place againafter the defrosting. On a sudden relaxation and an abrupt breaking offof the frozen points, the unwanted clicking noises can occur.

To eliminate, or at least substantially reduce, these clicking noises asa result of the freezing on and releasing again of the evaporator, ithas already been proposed to provide a sufficient spacing between theevaporator-module and the rear wall of the unit, whereby a freezing onshould be wholly avoided. Such a defined spacing, however, results in aloss of useful inner space.

It is therefore the underlying object of the present invention toprovide an improved refrigerator unit and/or freezer unit of the namedkind which avoids disadvantages of the prior art and further develops itin an advantageous manner. The clicking noises emitted by the evaporatorshould in particular be eliminated, or at least substantially reduced,without wasting valuable useful, inner space.

This object is solved in accordance with the invention by a refrigeratorunit and/or a freezer unit in accordance with claim 1. Preferredconfigurations of the invention are the subject of the dependent claims.

It is proposed for the avoidance of the aforesaid clicking noises,starting from the evaporator, to decouple said evaporator from the innertank of the refrigerator unit and/or freezer unit. In accordance withthe invention, the evaporator is provided with a multi-side jacket madefrom a soft, resilient and/or deformable padding material. A directfreezing together of the evaporator module and of the evaporatorenvironment, in particular of the cooling tank inner wall, is preventedby this jacket. A freezing together of the evaporator and of the paddingmaterial, on the one hand, or of the padding material and the inner wallof the unit, on the other hand, can admittedly occur. Relative movementsarising due to thermal strains can, however, be balanced by thedeformable padding material so that clicking noises arising due toconnection which break open suddenly are precluded. Strains and clickingnoises no longer occur due to the relative movements which take place inthe padding material. The construction space in the interior of the unitis nevertheless used to the best possible degree. No useful space islost by the jacket of padding material instead of the initiallymentioned large, defined air gap. In addition, the jacket can bringabout an air seal so that no external air can be directed past theevaporator, which would impair the energy efficiency. The paddingmaterial can in particular also have a thermal insulating function andcan accordingly act as a thermal insulator, which likewise has apositive effect on the energy consumption.

In a further development of the invention, the jacket is provided atleast on the contact sides of the evaporator with which the evaporatorcomes into contact with walls of the cooling tank, in particular of theevaporator accommodation space. The jacket is therefore provided wherethe evaporator could freeze on.

It may be optional for specific applications only to provide the jacketon the said contact sides partially, for example, in strip shape. Thejacket of insulating material, however, preferably covers the contactsurfaces of the evaporator over the whole area. Clicking noises can belargely completely eliminated by a full covering of the contact surfacesof the evaporator by the jacket of padding material. Care is preferablytaken in this context that also no open abutting edges remain, but thatalso the rim regions and edges of the evaporator housing are largelycompletely sheathed by the insulating material.

Different sides of the evaporator can form the contact surfacesdepending on the design of the evaporator. In accordance with apreferred embodiment of the invention, the jacket substantiallycompletely covers two wide sides and three flat sides of the evaporator.

The jacket can generally be made of different materials. In accordancewith an advantageous embodiment of the invention, the jacket comprises afoam, in particular a closed-cell polyethylene foam. The jacket isadvantageously resiliently deformable at least to a specific degree sothat it makes possible the described compensation movements.

In accordance with a particularly advantageous embodiment of theinvention, the jacket can be made at least partly hydrophobic, i.e.water repellant, with at least the surface of the jacket in particularbeing made hydrophobic. The jacket advantageously does not absorb anywater during the whole operating period of the unit. This can beachieved, for example, by a jacket made from a closed-cell foammaterial.

The jacket could generally be made in one piece. The evaporator could,so-to-say, be foamed in at its contact surfaces. The jacket preferably,however, comprises a plurality of foam pieces which are set in an exactfit onto the contact sides or contact areas of the evaporator andterminate flush with one another at their abutment edges so that no openabutment edges of the evaporator remain.

A slight thickness of the jacket of padding material in the range of afew millimeters can already be sufficient. Different wall thicknesses ofthe jacket can be provided on different sides of the evaporator inaccordance with an embodiment of the invention. The jacket can inparticular have a larger wall thickness on the side of the evaporatorfacing the refrigeration space than on the side of the evaporator remotefrom the cooling space and/or at flat sides of the evaporator. A heattransfer into the freezing space can hereby be suppressed or minimizedduring defrosting. For example, the jacket can have a thickness of 3 to5 mm on the side facing the interior space of the refrigerator unit anda thickness of 1 to 3 mm on the other sides of the evaporator. It is,however, understood that, in accordance with another embodiment of theinvention, a jacket is used having a uniform, sufficient wall thicknesson all sides of the evaporator.

In a further development of the invention, the jacket is connectedareally to the respective evaporator surface and is preferably fastenedthereto in a force-transmitting manner or in a firmly bonded manner. Thejacket made of foam can in particular be adhesively bonded to a sheetmetal jacket of the evaporator.

The evaporator can per also already be sufficiently fastened by anexactly fitting insertion into the evaporator accommodation spaceprovided therefor. The evaporator accommodation space is adapted forthis purpose with respect to its shape to the outer contour of theevaporator. Provision can preferably be made for the evaporator to beinserted into the evaporator accommodation space with a light press fitwhich is compensated by a light resilient deformation of the jacket. Inthis connection, the slightly compressed foam of the jacket holds theevaporator without wobble and secure against impact in the evaporatoraccommodation space.

Further fastening means can generally be completely dispensed with. Tonevertheless prevent a slipping of the evaporator on installation, inaccordance with an embodiment of the invention, the evaporator can befastened to the inner tank using a force-transmitting means, inparticular a screw. It has been found to be advantageous for theevaporator to be fastened to the inner container not by plastic plugs orplastic bayonet fittings, but rather by a plurality of screws atdifferent points of the inner tank. This further reduces the formationof clicking noises.

The evaporator accommodation space can generally be of variousconfigurations. In accordance with an embodiment of the invention, itcan comprise a substantially tub-shaped recess in the inner wall of thetank which can be closed by an inner cover. The evaporator can beinserted into the evaporator accommodation space in the inner tank fromthe inner space of the cooling tank. If the inner cover is then placedonto the tub-shaped recess to close it, the evaporator or the jacket ofpadding material applied thereto comes into contact with the tub base,the tub rims and the inner cover. It has been found to be advantageousfor the inner cover to have no webs projecting into the evaporatoraccommodation space at least in the region of the evaporator, but to befastened lying flat on the rims of the tub-shaped recess. Sealing beadsof padding material, in particular foam beads, can be provided forsealing at the rims of the inner cover and/or at the rims of thetub-shaped recess so that no clicking noises can arise between the innercover and the inner wall of the tank either.

The invention will be explained in more detail in the following withrespect to a preferred embodiment and to associated drawings. There areshown in the drawings:

FIG. 1: a schematic perspective overall view of a refrigerator unit inaccordance with a preferred embodiment of the invention;

FIG. 2: a perspective inner view of the cooling tank of the unit of FIG.1 with an open door which shows, in the rear wall of the cooling tank,the evaporator accommodation space provided therein and the evaporatorinserted therein;

FIG. 3: a perspective view of the evaporator of the unit from thepreceding Figures which shows the jacket of insulation material on thesheet metal jacket of the evaporator;

FIG. 4: a perspective view of an inner tank cover for the closing of theevaporator accommodation space in the rear wall of the cooling tank;

FIG. 5: a schematic representation of the freezing on conditions adoptedin the evaporator provided with a jacket and in a surrounding surface;and

FIG. 6: the freezing on conditions adopted in an evaporator without ajacket and in the surrounding surface.

The refrigerator 1 shown in the Figures includes a substantially cubiccooling tank 2 which can be closed by a door 3. The inner space 4 of thecooling tank 2 shown in FIG. 2 is bounded by the walls of an inner tank5. A tub-shaped recess 6 is formed in the rear side of the inner tank 5disposed opposite the door 3 and bounds an evaporator accommodationspace 7 in which the evaporator 8 is accommodated. A fan 9 isaccommodated in the tub-shaped recess 6 in addition to the evaporator 8in the embodiment drawn and is arranged at the upper rim of the recess6.

The tub-shaped recess 6 is substantially rectangular, with the loweredge (cf. FIG. 2) being configured slightly inclined toward the center.

The tub-shaped recess 6 can be closed by an inner cover 20 which isshown in FIG. 4, is adapted to the contour of the recess 6 with respectto its outer contour, is seated on the peripheral rim 11 of the recess 6and can be fastened there. The inner cover 20 is seated in as airtight amanner as possible on the side rims 11 to the right and left of therecess 6, which can be achieved, for example, by the application of foambeads onto the said rims 11. The inner cover, however, is not seated inan air-tight manner on the rim 11 of the recess 6 at its lower end sothat air can be sucked in here. The fan 9 shown in FIG. 2 sucks in airover this gap between the lower section of the rim 11 of the recess 6and the inner cover 20 so that said air flows upwardly over theevaporator 8 and flows out again at the fan opening provided at theupper end of the inner cover 20.

As FIG. 2 shows, the evaporator 8 is seated with an exact fit in thetub-shaped recess 6. Its two vertical flat sides as well as its lowerflat side are seated with an exact fit on the side walls of thetub-shaped recess 6 and are in contact therewith. Toward the upper side,the evaporator accommodation 7 is made larger than the evaporator sothat free space remains which accommodates the infeeds and outfeeds ofthe evaporator as well as further cables.

The evaporator 8 furthermore corresponds with respect to its thicknessapproximately to the depth of the tub-shaped recess 6 which would haveto be measured perpendicular to the plane of the drawing in FIG. 2. Ifthe inner cover is set over the tub-shaped recess 6 in the inner tub 5to close it, a contact of the evaporator 8 is adopted to the base of therecess 6, on the one hand, and to the inner cover, on the other hand.Although the evaporator 8 would per se be accommodated with an exact fitin the evaporator accommodation space 7 and would per se be sufficientlyfastened, the evaporator can be screwed on by a screw connection,preferably to the base of the tub-shaped recess 6. This in particularprevents an upward sliding of the evaporator into the hollow spaceaccommodating the tubing or cabling, e.g. during installation.

As FIG. 3 shows, the evaporator 8 is sheathed by a jacket 12 made ofclosed-cell hydrophobic foam. The jacket 12 covers the contact surfacesof the evaporator housing 8 in each case over the whole surface, theevaporator 8 contacting the walls of the tub-shaped recess 6 as well asthe inner cover with said contact surfaces. The evaporator 8 itself hasan aluminum sheet metal jacket which forms the said contact surfaces andso-to-say forms a housing of the evaporator 8. The jacket 12 of foam isadhesively bonded to this aluminum metal jacket areally so that theevaporator 8 is sheathed on all sides at the said contact surfaces.

If the evaporator 8 has the prescribed jacket 12 of soft, yieldingpadding material, the freezing state shown in FIG. 5 results if arepeated cooling down takes place after a defrosting procedure. Thesurface of the evaporator 8 can admittedly freeze together with thejacket 12 on the one hand, and the jacket 12 with the surface of theunit surroundings, on the other hand, in particular with the inner unitwall of the recess 6. In FIG. 5, an ice film is shown in each casebetween the jacket 12 and the evaporator 8 as well as between the jacket12 and the recess 6. If relative thermal movements occur between theevaporator 8 and the inner wall of the unit, they would result in abreaking off of the frozen ice drops without the jacket 12. The jacket12 can, however, compensate these relative movements and therefore avoidcorresponding clicking noises.

In contrast to this, FIG. 6 shows the direct freezing on of anevaporator 8 without a jacket directly to the inner surface of therecess 6, as would occur in the prior art without the jacket 12 inaccordance with the invention. If relative movements occur here, theycannot be compensated and the unwanted clicking noises occur.

1. A refrigerator unit and/or a freezer unit comprising a cooling tank(2) as well as an evaporator (8) which is accommodated in an evaporatoraccommodation space (7) in the cooling tank (2), wherein the evaporator(8) has a multi-sided jacket (12) of a soft resilient and/or yieldingpadding material.
 2. A refrigerator unit and/or a freezer unit inaccordance with claim 1, wherein the jacket (12) is provided at least onall contact sides of the evaporator (8) with which the evaporator (8)comes into contact with walls of the evaporator accommodation space (7).3. A refrigerator unit and/or a freezer unit in accordance with claim 2,wherein the contact surfaces (13, 14, 15, 16, 17) of the evaporator (8)are completely covered by the jacket (12).
 4. A refrigerator unit and/ora freezer unit in accordance with claim 1, wherein the jacket (12)substantially completely covers two wide sides (16, 17) and/or aplurality of flat sides or end face sides (13, 14, 15) of the evaporator(8).
 5. A refrigerator unit and/or a freezer unit in accordance withclaim 1, wherein the jacket (12) comprises a foam, in particular aclosed-cell polyethylene foam.
 6. A refrigerator unit and/or a freezerunit in accordance with claim 1, wherein the jacket (12) is made atleast partially hydrophobic, in particular has a hydrophobic surface. 7.A refrigerator unit and/or a freezer unit in accordance with claim 1,wherein the jacket (12) is made permanently free of water absorption. 8.A refrigerator unit and/or a freezer unit in accordance with claim 1,wherein the jacket (12) is made in multiple pieces, preferably comprisesa plurality of plates, which each cover an evaporator side.
 9. Arefrigerator unit and/or a freezer unit in accordance with claim 1,wherein the jacket (12) is connected to the respective evaporatorsurface areally, preferably in a force-transmitting manner and/or afirmly bonded manner, in particular adhesively bonded.
 10. Arefrigerator unit and/or a freezer unit in accordance with claim 1,wherein the jacket (12) is connected to the respective unit surfacesurrounding the evaporator (8) areally, preferably in aforce-transmitting manner and/or a firmly bonded manner, in particularadhesively bonded.
 11. A refrigerator unit and/or a freezer unit inaccordance with claim 1, wherein the evaporator (8) is inserted into theevaporator accommodation space (7) with an exact fit, preferably with aslight press fit which slightly compresses the jacket (12).
 12. Arefrigerator unit and/or a freezer unit in accordance with claim 1,wherein the evaporator accommodation space (7) has a tub-shaped recess(6) in an inner wall of the cooling tank (2) which can be closed by aninner cover.
 13. A refrigerator unit and/or a freezer unit in accordancewith claim 1, wherein the inner cover is made without webs projectinginto the evaporator accommodation space at least in the region of theevaporator (8) and can preferably be placed flat on a rim (11) of thetub-shaped recess (6).
 14. A refrigerator unit and/or a freezer unit inaccordance with claim 1, wherein the evaporator (8) is fastened by ascrew connection to the inner wall of the cooling tank (2).
 15. Arefrigerator unit and/or a freezer unit in accordance with claim 1,wherein the evaporator (8) is made as a lamellar evaporator and/or has asheet metal jacket to which the jacket (12) of insulation material isapplied.
 16. A refrigerator unit and/or a freezer unit in accordancewith claim 2, wherein the jacket (12) substantially completely coverstwo wide sides (16, 17) and/or a plurality of flat sides or end facesides (13, 14, 15) of the evaporator (8).
 17. A refrigerator unit and/ora freezer unit in accordance with claim 3, wherein the jacket (12)substantially completely covers two wide sides (16, 17) and/or aplurality of flat sides or end face sides (13, 14, 15) of the evaporator(8).
 18. A refrigerator unit and/or a freezer unit in accordance withclaim 17, wherein the jacket (12) comprises a foam, in particular aclosed-cell polyethylene foam
 19. A refrigerator unit and/or a freezerunit in accordance with claim 16, wherein the jacket (12) comprises afoam, in particular a closed-cell polyethylene foam
 20. A refrigeratorunit and/or a freezer unit in accordance with claim 4, wherein thejacket (12) comprises a foam, in particular a closed-cell polyethylenefoam